Wood chips can be mass produced with a long-timber chipping machine, as described for example in the present assignee's German patent publication DE 43 35 348 (hereafter the "first Publication"). Here, the chipping machine includes a timber feed channel for receiving timbers to be chipped in a longitudinally arranged form and includes a timber-advancing device for feeding the longitudinally arranged timbers to a chipping tool or device positioned at the downstream end of the feed channel. The chipping device includes a rotatable cutter ring, the cylindrical inner wall thereof defining a chipping chamber, which is aligned with the feed-channel downstream end. The cutter-ring inner wall carries evenly spaced chipping cutters. Here, the chipping device moves upwardly from its bottom dead center relative to the feed channel during the chipping operation.
In comparison with a horizontally moving chipping device, the aforedescribed vertically moving chipping device advantageously results in a shortening of the actual chipping section and leads to the advantages disclosed in the first Publication. Notwithstanding the advantages and success derived from the chipping machine of the type disclosed in the first Publication, the following problem may arise in certain arrangements. When the last section to be chipped of a bundle of long timber pieces is introduced, the device does not effectively support or guide all of the timbers of this section into the chipping chamber. The timber pieces of the last section can thus drop into the continuously rotating cutter ring in a more or less uncontrolled manner. Because the timber pieces tilt downward as they drop into the rotating cutter ring, the cutter ring can turn the timber pieces in the opposite direction before the rams, which project into the chipping chamber from the above, can clamp them down.
German publication DE 25 42 340 A1 (hereafter the "second Publication") also discloses a timber chipping machine, but its rotatable cutter ring is stationary. Instead, it uses a timber receiving bin having a movable platform to press the timbers against the various positions of the rotating cutter ring. The movable platform is curved to match the curvature of the rotating cutter ring. The loading bin is aligned with the receiving bin on the open side of the chipping ring and also has a base having a curvature matched to the curvature of the movable platform. The loading bin is pivoted between a vertical position (timber removing) and a tilted position (timber receiving) by a piston/cylinder unit. Here, the conveyor drops the timbers through the tilted loading bin's upper opening, which is positioned below the downstream end of a conveyor. After the loading is completed, the loading bin is pivoted into its vertical unloading position. A discharge pusher pushes the timber from the loading bin into the receiving bin and thus onto the curved platform. After the pusher is withdrawn, the platform is raised continuously via a piston/cylinder unit to bring the timber into engagement with the rotating cutters.
The chipping machine type disclosed in the second Publication has shortcomings too in that it is not feasible for chipping long-length timbers. Rather, it is severely limited to a relative short timber (the length substantially the same as or shorter than the chipping cutter length.
Accordingly, there is a need for a long-timber chipping machine without the aforementioned shortcomings associated with the known timber chipping devices. The present invention fulfills this need.